int main(void) { /*HW semaphore Clock enable*/ __HAL_RCC_HSEM_CLK_ENABLE(); /* Activate HSEM notification for Cortex-M4*/ HAL_HSEM_ActivateNotification(__HAL_HSEM_SEMID_TO_MASK(HSEM_ID_0)); /* Domain D2 goes to STOP mode (Cortex-M4 in deep-sleep) waiting for Cortex-M7 to perform system initialization (system clock config, external memory configuration.. ) */ HAL_PWREx_ClearPendingEvent(); HAL_PWREx_EnterSTOPMode(PWR_MAINREGULATOR_ON, PWR_STOPENTRY_WFE, PWR_D2_DOMAIN); /* Clear HSEM flag */ __HAL_HSEM_CLEAR_FLAG(__HAL_HSEM_SEMID_TO_MASK(HSEM_ID_0)); /* STM32H7xx HAL library initialization: - Systick timer is configured by default as source of time base, but user can eventually implement his proper time base source (a general purpose timer for example or other time source), keeping in mind that Time base duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and handled in milliseconds basis. - Set NVIC Group Priority to 4 - Low Level Initialization */ HAL_Init(); /* Infinite loop */ while (1) { } }

This is a code snippet written in C programming language for an STM32H7 microcontroller.

The `__HAL_RCC_HSEM_CLK_ENABLE()` function enables the clock for the Hardware Semaphore (HSEM) module.

The `HAL_HSEM_ActivateNotification()` function activates the HSEM notification for the Cortex-M4 core.

The `HAL_PWREx_ClearPendingEvent()` function clears the pending event in the power management module.

The `HAL_PWREx_EnterSTOPMode()` function puts the Cortex-M4 core into the STOP mode with the main regulator ON, waiting for the Cortex-M7 core to perform system initialization.

The `__HAL_HSEM_CLEAR_FLAG()` function clears the HSEM flag.

The `HAL_Init()` function initializes the STM32H7xx HAL library.

The infinite loop at the end of the code keeps the microcontroller running indefinitely.